Jaw muscles, how do they work?

With a face like a brick and quite pronounced fangs, they probably work well enough.

Sketched a couple gorgonops skulls. Have no idea about the species, will probably end up being a mishmash amalgam much like my theropod ravings. Started from ten o clock, then progressed clockwise around the paper, finishing with the fellow who seems to be having back problems. Still needs a truckload or three of fixin'

Might end up being a new character. Speaking of which, I don't really have character sheets for my characters.